Wheel and process of tiring same



Patented Nov. I. I898.

H. M. DU BUIS. WHEEL AND PROCESS OF TIRING SAME.

( Application filed July (No Model.) 3 Shaats-Sheet I.

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No. a|s,257.

Patented Nov. I, I898. H. M. DU BOIS. WHEEL AND PROCESS OF TIRING SAME.

(Application filed July 30, 1897.)

3 Sheets-Sheet 2.

(N0 Modem Hozqard.

Nu, 6|3,257 Patented Nov. I, I898.

' H. M. DU BDIS.

WHEEL AND PROCESS OF TlRING SAME.

(Application filed July 30, 18974) 3 Sheets-Sheet 3,

(No Model.)

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UNITED STATES PATENT ()FFIQE.

HOWARD MALCOLM DU BOIS, OF ASHBOURNE, PENNSYLVANIA.

WHEEL AND PROCESS OF TIRING SAME.

SPECIFICATION forming part of Letters Patent No. 613,257, dated November 1, 1898.

Application filed July 30, 1897. Serial No. 646,496. (No model.)

To a whom it may concern:

Be it known that I, HOWARD IVIALOOLM DU 13015, a citizen of the United States, residing in Ashbourne, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Wheels and Processes of Tiring the Same, of which the following is a specification.

This invention relates to wheels, and more particularly relates to an improved process of tiring the same.

The object of the invention is to provide an improved process in the use of which many serious disadvantages and defects heretofore developed in the process of tiring wheels are avoided, whereby wheels of greater durability and strength are secured.

A further object of the invention is to provide an improved cushion-tired wheel adapt-,

ed to reduce the noise and rattling thereof to a minimum.

In the drawings accompanying and forming part of this specification, Figure l is a side elevation of a vehicle-wheel embodying this invention, a part thereof being shown in section, thereby more clearly to illustrate the construction of the tire. Fig. 2 is a transverse section of the felly and tire shown in Fig. 1 and illustrates, on an enlarged scale,

the tire and the compressible elastic material in juxtaposition to each other before said tire is compressed on the telly. Fig. 3 is a view similar to Fig. 2, but illustrates the position of the tire and the elastic material after the tire has been compressed beyond its normal working position or the position which it assumes in the finished wheel. Fig. 4 is a View similar to Figs. 2 and 3, but illustrates the position of the tire and the elastic material when said tire has assumed its normal position in the finished wheel. Figs. 5 and 6 are partly-sectional views of a wheel, illustrating the tire in the positions corresponding to Figs. 2 and 4, respectively. Figs. 7, 8, 9, and 10 are partly-sectional views of a wheel for illustrating successive stages of the process hereinafter set forth, and Fig. 11 is a diagrammatic view of one means whereby one step of this process may be carried out.

Similar characters of reference designate like parts in all the figures of the drawings.

Heretofore various processes have been used to tire wheels, the two leading processes, however,being, respectively, thatin which the tire is heated and while so heated placed on the felly and then permitted to contract thereon and that in which the tire is cold-compressed or upset on the wheel-rim. In each of these processes, however, serious disad' vantages and defects exist, and therefore the present process is an improvement thereon and in the use of which present process the defects and disadvantages appertaining to each of said processes are avoided. In order, however, to clearly point out the differences between this improved process and the processes above mentioned and also to point out the defects and disadvantages which are avoided by the use of thisimproved process, it is necessary to refer to the construction of wheels as heretofore generally made. For this purpose Fig. 7 represents the woodwork of a wheel as usually made and which comprises the hub, spokes, and rim, the hub thereof being shown broken away to illustrate the position assumed by the spoke-tenons when the wheel is completed or when in a technical sense it is driven straightthat is to say, if aline be drawn, as at a, it will fall directly through the center of the rim and tenon and pass through that portion of the hub where the axle-box is to be placed, so that when said box is set this line falls through its center. The shoulders 2 of the spokes where they rest upon the hub 3 are intended to be constructed in such manner that when the tire is applied the wheel will, if possible,possess the usual amount of dish or concavity without in any way straining or disarranging the joints, thereby keeping the woodwork of the wheel in proper position, which is one of the vital points in wheel-male ing and to which the durability of the wheel in service is largely due. In Fig. 8 is illustrated the wheel as it should appear after the tire has been placed thereon-for instance, by heating and subsequent contraction by cooling-the dish or concavity being indicated by the dotted line b, the dotted line a representing the plumb or load line, as shown in* Fig. 7. The tiring of wheels, however, by heating the tires and then permitting the subsequent contraction thereof by cooling has serious objections, one of which is the ex- Ice pense, while it is furthermore largely dependent on the skill of the workman in making proper allowance for draft or shrinkage, the surface of the wheel-rims, moreover, being in danger of burning. Furthermore, since the tendency of the tire after being heated is to returnonly to its original or normal position, it follows that if it fails to do this properly or the woodwork contracts or shrinks the tire soon works loose and rattles. For these reasons this process has been for some constructions of wheels superseded by the other process, ordinarily termed cold upsetting, in which an upsetting-machine is used to apply a welded tire, whereby it is compressed or u pset on the felly of the wheel. This process, however, likewise has serious objections as well as disadvantages, since, as is well known, all metals possess an elastic limit and that up to the point of such elastic limit there is a rebound or reaction from any pressure applied thereto. It is therefore found in practice that to cold-compress tires upon wheels it is necessary to compress the tire beyond its elastic limit in order to permit the tire to have a permanent set and prevent rebound or return to its original position,whereby the woodwork is also pressed far beyond the dish line, so that the spokes and tenons are under comparatively great strain, as indicated by line b, Fig. 9, which indicates the approximate point of greatest compression. On removing the pressure the consequent reaction of the metal toward its elastic limit or its normal position in the finished wheel permits the wheel substantially to recover its position; but it will be seen that the woodwork, being constructed to resist the gradual strain or draft, is under such pressure practically brought to the point of disruption, as the shoulders 2 of the spokes instead of remaining in the position shown in Fig. 8 are by such pressure necessarily sunken into the forward part of the hub 3, as shown at 4, Fig. 9, while the rear parts of said spokes are to a certain extent drawn out, as at 5, and in some instances the fibers of the wood are broken or cracked. Moreover, this compression of the woodwork to a point beyond the proper limit is destructive to the rim-tenons (3, which it is necessary to have remain perfectly solid, and hence, as the durability of the wheel materially depends upon the shoulders of the spokes resting upon the hub and the solidity of the rim-tenons, it follows that under this great pressure, no means being provided to render the same ineffective on the woodwork, the wheel must necessarily be weakened. The amount of pressure necessary to secure the proper upsetting of the tire can be more readily seen by an inspection of Fig. 10, from which it will be observed that when the upsetting instrumentality is in operation the wheel will be forced into the position indicated by dotted lines o, and when this pressure is removed the wheel assumes its normal finished position. During this step, however, the woodwork of the Wheel, as

above stated, is more or less injured, as the joints of the hub and rim of the spokes being the weakest points and the wood being incapable of standing the same amount of pressure as the metal tire it follows that when the tire has been compressed beyond the point of its elastic limit or normal position in the finished wheel the spokes will yield first at their weakest points to permit such compression, whereupon when the pressure is removed from the tire and thesame returns to its said normal position the spokes and the rim fail to entirely follow up the tire, the result being that the tire in a very short time will work loose and the entire wheel become weakened and unfit for use. Not only this, but, owing to the destructive compression of the wood which must take place, the fibers of the same are more or less injured, thereby weakening and consequently impairing the durability of the wheel. By means of my improved process, however, I have found that by overcoming or rendering nugatory this destructive pressure on the woodwork of the wheel an improved wheel is secured in which not only is the tire cushioned, but it is firmly held in position against displacement and rattling.

This improved process consists, in a general way, in applying some suitable compressible elastic substance or material to the periphery of the felly or rim tread of a wheel or to the inner face of a welded or non-jointed tire, whereby it will be intermediate such felly or rim tread and the inner face of said tire, then applying the tire, made of excess size, to the wheel, and then simultaneously at all points peripherally forcing on said tire by cold-compression, whereby the elastic material will permit the tire to be compressed beyond its elastic limit, and will transmit a sufficient amount of such pressure to the woodwork of the wheel to secure the proper dish or concavous formation thereof, but will receive the excess of pressure beyond the point of resistance of the woodwork and the elastic limit of the tire, and hence prevent a destructive pressure from being transmitted to such woodwork, so that while the tire can be compressed beyond its said elastic limit for properly securing the same in its permanent set position the woodwork will not be destructively compressed, as heretofore.

In carrying out this improved process in the preferred mode thereof herein set forth I place a compressible elastic substance 8 of any suitable material-for instance, such as rubber or other analogous composition-in position relatively to the wheel so that it will be intermediate the tread 9 of the rim 10 and the inner face 12 of the tire 13 when said tire is in position, and I accomplish this by either placing it directly around the rim-tread or by placing it on the inner face of the tire, temporarily securing it in such position by the use at different points of a small quantity of cement or other suitable material. The tire is shown channeled or provided with in- IIO wardly-extending flanges 14 and let, shown in the drawings as slightly tapered, whereby the inner edges thereof are adapted when in position to be substantially flush with the sides 15 and 15 of the felly or rim 10, which is also usually somewhat tapered. It will be understood, however, that in practice these flanges may be made at right angles to the inner face of the tire. By this construction of tire an annular closed channel or space is obtained between the Wheel-rim tread 9 and the inner face 12 of the tire when the latter is on the felly, the four walls of said space being formed by the rim or felly tread 9 of the woodwork and the inner faces or walls of the flanges 14 and 14 and said inner face 12 of the tire. The tire is then placed loosely in position on the wheel, the said elastic material preferably not quite filling widthwise the channel, whereby space is allowed for fiowage or spreading of such elastic material when the tire is reduced for putting the elastic material under compression. The wheel thus provided with its loosely-fitting tire is then placed in some suitable u psettingmachine, herein represented in Fig. 11 of the drawings as a series of plungers or dies 20, adapted to engage the outer face of the tire around the entire periphery thereof, whereby when power is applied by some suitable means (not shown) the dies or plungers, working radially, will cold-compress and'upset the metal of the tire to first close in the annular space between said tire and felly and then reduce the volume of said closed space by a further reduction of the size of the tire to the point of subjecting the elastic material to compression at all points simultaneously throughout the mass of such material, whereby the tire will be compressed beyond its elastic limit or its normal position in the finished wheel. The excess of pressure, however, needed to compress the tire beyond its said normal position in stead of temporarily forcing the wheel out of proportion with an excessive amount of dish, as heretofore necessary-in order to secure the required dish, simply disturbs the woodwork sufficiently to secure the proper amount of concavity without injury to the joints or fibers of the wood. From this it will be seen, Fig. 3, that when the wheel is under the greatest amount of compressionin other words,when the tire has been pressed beyond its elastic limit or its normal position or size in the finished wheel-the rubber has been caused to fiow or spread laterally over the entire surface of the rim-tread 9, thereby entirely filling up the closed annular space, and has been just under a sufficiently-high pressure to permitaproportionate amount of such pressure to be transmitted to the woodwork of the wheel, thereby to secure the desired amount of dish. When, however, such pressure is removed and the tire permitted to expand outward to its normal position in the finished wheel, the rubber will follow the tire and take up the space made by the recovery of the metal, and thus retain the woodwork in its proper dish position. The woodwork being under such compression reacts against and maintains the rubber intermediate the rim-tread and the wheel-tire constantly under compression, whereby the tire will always be held firmly in position and properly cushioned. Furthermore, it will be seen that as the metal tire is affected by the variations of temperature and the woodwork affected by the variations of moisturethat is to say, for instance,when the tire expands in hot weather and the woodwork ,shrinks by dryingthe elastic material acts as an equalizer between such tire and woodwork. To have the elastic material eflt'ectual for this purpose, however, it must originally be put under an initial pressure greater than can be obtained by merely closing in the same at one edge thereof as heretofore practiced, since by this mode of constructing a cushioned wheel the elastic material on the closing in of its edge flows out through the closing-space, so that there is retained in the cushion-space a volume of elastic material only slightly in excess of the volume of such space and in practice actually less than is required to overcome or equalize the changes in the tire and woodwork due to the variations of heat and moisture, respectively.

In carrying out this improved process, especially when ordinary vulcanized rubber of commerce is used, the rubber should be subjected to a pressure considerably beyond the point of flowage, whereby the elastic material will exist in a state of compression sufficient to effectually resist the opening of the seg ments of the felly, while retaining a considerable degree of resiliency when subjected to ordinary requirements.

In conclusion it will be seen that wheels having tires fitted thereto in accordance with this improved process must necessarily be more durable than wheels heretofore produced under the old process, since the woodwork of the wheel in the present improved process does not have to be destructively pressed to permit the tire to be forced beyond its elastic limit or normal position in the finished wheel, for while substantially the same amount of pressure may be given to the tire as heretofore, thereby to press the same be yond its said normal position in the first instance, this excess of pressure is not transmitted to the woodwork, but is taken up by the intermediate elastic material.

The foregoing results I have practically demonstrated by recently placing on the market large quantities of wheels manufactured in accordance with this improved process and have found that they are more durable and are capable of withstanding greater strain than wheels ordinarily constructed, in which the tires are applied thereto by the heating or by the cold-compression of the same, as heretofore practiced.

By the term compression as used herein in connection with the elastic material is meant that the material is changed in shape to place it under a high pressure, whereby its expansive force is considerable, the volume of the material, however, remaining approximately the same.

Having thus described my invention, I claim- 1. That improvement in the art of making wood-felly cushioned wheels, which consists in assembling together the three parts comprising a metal channel-tire of excess size, the wood felly of the wheel, and an elastic cushion, with the channel-tire located around the folly and with the elastic cushion located between said tire and said felly; then reducing said channel-tire by cold-upsetting and thereby first making an annular closed space between the channel-tire and the wood felly and containing the elastic cushion; next reducing the volume of said closed space by a further reduction of the size of the channeltire and thereby subjecting said cushion simultaneously at all points to compression, wherebysaid channel-tire is first compressed beyond its elastic limit and the woodwork of the wheel to the required eoncavous or dished formation, the excessive pressure between the point of resistance of said woodwork and the elastic limit of said tire being received by said cushion; and then removing such pressure to permit the tire to return to its normal position in the finished wheel intermediate its original excess-size position and that position which it assumed while under the greatest compression.

2. The herein-described cushioned wheel, it comprising a metal tire having a tread with in Wardly-extendin g flanges at the edges thereof forming an annular channel within the tire; a wood felly extending around the wheel and located between the inner edges of said tirefianges, thereby closing said annular channel within the tire; and an elastic cushion of rubber or like cushioning material filling said channel between said tire and said felly, said wheel having its channel tire first made of excess size and then reduced by upsetting first to make the annular closed channel between said tire and the wood felly, and next bya further reduction of the size of the channel-tire subjecting said cushion simultaneously at all points to compression, whereby the wheel when completed has the pressure of the tire transmitted through said cushion to the wood felly and whereby the woodwork of the wheel is during manufacture preserved from destructive compression and the completed wheel made self-adj usting to the variations of its members by changes of heat and moisture, substantially as described.

3. A vehicle-wheel comprising a rim, a channel-shaped tire cold-compressed on said rim and forming therewith a closed annular space, and a compressed elastic material in said space having its volume completely filling said closed annular space on the cold-upsetting of said tire.

HOWARD MALCOLM DU BOIS. lVitnesses:

C. A. WEED,

EDWARD A. MEAD. 

